stem-group bilaterians Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
Count: -
   Family †Siphusauctidae O'Brien & Caron, 2012
  Count: [†*] †1g;1s
     Genus †Siphusauctum O'Brien & Caron, 2012
    Count: [†*] †1s
       †Siphusauctum gregarium O'Brien & Caron, 2012
      Count: -